The interior of Larry's apartment was the only set built for this film.
Director Paul Mazursky starred in Medo E Desejo (1952) by Stanley Kubrick. The Christopher Walken character, Robert Fulmer, is based on Howard Sackler, the writer of Medo E Desejo (1952).
Debut theatrical feature film of actor Bill Murray who appears uncredited as Nick Kessel. He has a couple scenes as a crowd extra.
Woody Allen appears in an uncredited cameo as Jake, an old bearded love-poem seller, in the film's first bar scene. Director Paul Mazursky would direct Allen as an actor again, this time credited, in the later feature film 'Scenes from a Mall' (1991).
Woody Allen: Uncredited, the New York actor-writer-director, heavily made-up in make-up with a thick beard making him virtually unrecognizable, as Jake, an old love-poem seller, seen in the film's first bar scene early in the movie.